Process of producing salts of potassium and aluminum and fixed nitrogen compounds.



. citizen of the United States, residing at Chi- SkMUEL PEACOCK. OF CHICAGO, ILLINOIS, ASSIG-NOR TO INTERNATIONAL AGRICUL- TUBAL CORPORATION, OF NEW YORK, N. Y., A CORPORATION 'OF NEW YORK.

PROCESS OF PRODUCING SALTS OF POTASSIUM AND ALUMINUM AND FIXEDNITROGEN COMPOUNDS.

Specification of Letters Patent.

1 Patented Feb. 23, 1915.

No Drawing. Original application filed July 8, 1912, Serial No. 708,277. Divided and this application fil-ed August 14, 1913. Serial No. 784,836. 1

To all whom it may concern;

Be it known that I, SAMUEL, PEACOCK, a

cago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Processes of Producing Salts of Potassium and Aluminum and Fixed Nitrogen Compounds; and Ido herebydeclare the following to be a full, clear, and exact description of the invention, as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a process of separating potassium and aluminum from their silicate combinations, While at the same time producing car'bids and nitrids of these metals which may be utilized in the production of other compounds.

This invention is divided from my copending application #7 08,27 7 filed July 8, 1912, entitled Process of separating potassium and aluminum from their silicate combinations, and has for its object the attainment of the above results in a simple, expeditious and comparatively inexpensive manner and to these ends consists in the novel steps constituting my process, all as will be more fully hereinafter disclosed and particularly pointed out in the claim.

In carrying out my process I finely divide a potassium bearing silicate rock such as a natural ortho-clase or microcline, having a formula such as KAlsi O and mix the same with a suitable quantity of finely divided carbon such as ground coke, coal dust or other form of fuel carbon. The mixed carbon and silicate is then heated to a temperature of about 1200 C. to 14:00 O. in an atmosphere containing substantially no free oxygen, when it is found that potassium and aluminum are separated in the form of carbids, such as K 0 and Al C respectively. The reactions which take place may be stated as follows If the reaction is carried out in an atmosphere of nitrogen, free from air, then the potassium and aluminum are separated as nitrids such as K N and Al N respectively; or as carbo-nitrids such as K,ON

such

and Al C N respectively; or as a mixture While potassium and aluminum silicates are decomposed at the temperatures and under the conditions stated, the velocity of the reaction is greatly increased by raising the temperature to say 1500 C. in the first instance and to 1700 C. in the second example. Further, the decomposition of the silicate is greatly facilitated by maintaining low partial pressures of the products of the reaction. This may be accomplished by carrying out the process in a gas tight furnace through which the mixture is continuously fed, while nitrogen or nitrogen containing gas is admitted at the discharge'end and continuously drawn through and out of the furnace at the feed end, or vice versa, and if desirable a vacuum pump at the end of the furnace may be used to maintain the partial pressures at any desired values. But I pre fer to maintain low partial pressures by simply flushing the furnace continuously or at intervals during the process either with nitrogen, or with an inert or neutral gas such as hydrogen producerrgas or even with ordinary fuel or illuminating gas.

Iam not as yet able to say with certainty just what, atomic linkages are involved in the products actually produced, but from the presence of combined carbon and combined nitrogen (when nitrogen is present in the furnace), and from other considerations,

- I believe the normal valenciespersist, and

that-the above compounds are the ones produced in the greatest quantities although there may be others present in smaller protemperature is high and the partial pres sures kept low by flushing with nitrogen mentioned I am enabled to separate from its associated compounds the potassium and aluminum in silicates and todisperse them. These compounds may next be burned with an excess of air in any suitable apparatus to form potassium carbonate K CO and aluminum oxid, Al O When the metal nitrids are present in sufficient quantity to render the recovery of their nitrogen profitable, they may be transferred from the furnace to an autoclave and treated with superheated steam at a pressure of say not less than five atmospheres, when the following reactions "take place On the other hand when the metal carbonitrids are present in sufiicient quantity to render the recovery of their combined nitrogen desirable, they may be likewise placed in an autoclave, and treated with superheater steam as above, when the following reactions will take place In treating the furnace products with superheated steam, any metal carbids that might be present will break up as follows In the step oftreating the furnace prod ucts with superheated steam the velocity of the reaction may becontrolled by regulating the pressure of the steam. At five atmospheres pressure the reaction velocity is rather slow;- as the pressure and therefore the temperature increases, however, the reaction velocity increases in accordance With Well known thermodynamic laws.

It is obvious that those skilled in the art may vary the details of my process without departing from the spirit thereof, and therefore I do not wish to be limited to the above -on the other hand, the temperature 1s not carried high enough to .produce such carbonitrids, in quantity, but only sufiiciently high to produce carbids, and incidentally, small proportions of nitrids. In other words, the temperature used in this application is so low as not to require electric heat, the process being carried out at the temperatures furnished by the combustion of ordinary fuel.

What I claim is The process of producing fixed nitrogen compounds which consists in heating a mixture of carbon and a silicate, bearing potassium and aluminum, in an atmosphere of nitrogen to a temperature below 1600 C. sufficient to bring about the reaction; collect ing the products thus produced; and treat ing them with steam at a temperature sufficient to produce the desired nitrogen compounds, substantially as described.

In testimony whereof I aflix my signature, in presence of two witnesses.

SAMUEL PEACOCK.

Witnesses:

T. A. WITHERSPOON, JAs. I-I. BLACKWOOD. 

